Why is my Bootstrap 5 hover class not working?

Solution for Why is my Bootstrap 5 hover class not working?
is Given Below:

I’m trying to change the bootstrap button into a hover but it’s not working.

HTML:
<button type="button" class=" btn btn-dark">Sign Up</button>

CSS:
.btn-dark:hover { color: blue }

Most likely because of the css specifity:

Use .btn.btn-dark:hover { color: blue } (i.e. all classes for that element combined in the css selector) to overwrite the regular rule for that element.

Have you included your custom CSS file after your bootstrap css include?
This makes a difference as it will read your custom tag last and apply that over the bootstrap style.

also you could overwrite the scss file.
https://www.bootstrapdash.com/bootstrap-css-styles/